1. Description of the Core The Molecular Pathology and Imaging Core (MPIC) was established in 1995 as the Morphology Core, as part of the Program Project Differentiation of Tissues Involved in Nutrition and Metabolism (DK049210). In 1997, MPIC expanded to provide services and reagents to investigators (i.e. members and associate members) of the Center for Molecular Studies in Digestive and Liver Disease (CMSDLD; P30DK50306) and, in 2003, became part of an additional Program Project, Mechanisms of Esophageal Carcinogenesis (CA098101). The additional funding through the CMSDLD and the second P01 allowed MPIC to grow significantly by expanding services, equipment, space, and personnel, with tremendous benefits, as detailed below, to CMSDLD investigators. The name change, instituted this year, reflects a marked expansion of Core services and equipment. Through the years. MPIC has remained independent, rather than become an open, school-wide facility, in order to preserve focus and serve the needs of its dedicated clientele. Thus, use of the facility is restricted to CMSDLD investigators and investigators of the two P01s. Currently, MPIC comprises 4 rooms and 1153 square feet (Figure 1) on the 6^ floor of the Clinical Research Building (CRB), adjacent to many of the GI research laboratories; a recent addition expanded the size of MPIC by more than 70%. MPIC now includes the following: two large laboratories (CRB 602 and 675) with 8 total benches and 2 chemical hoods, each containing a complete set-up for performing in-core immunohistochemistry (IHC), immunofluorescence (IF), and in-situ hybridization (ISH) a tissue processing room (CRB 610B) with a chemical hood an adjacent small room (CRB 608) housing the confocal microscope and laser capture micro-dissection (LCM) apparatus. office space (adjoining CRB 675) for the technical director with computer and telecommunications MPIC has been extremely successful since its inception, has been heavily utilized, and has served as a model core facility for numerous other program projects and centers both at the University of Pennsylvania and throughout the country. Moreover, MPIC has continually improved its ability to provide quality services in a timely manner to CMSDLD investigators. MPIC assesses nominal charges for tissue processing and sectioning, special staining, confocal microscopy, and laser capture microdissection; all other core services are available at no cost to CMSDLD investigators and their laboratories; MPIC services are particularly valuable to associate members, many of whom do not yet have independent funding, and Pilot and Feasibility (P/F) awardees. MPIC was reviewed recently through the competitive renewals of the two supporting P01 grants (P01 DK049210 was reviewed in 2008 and P01 DK049210 in 2011) and was judged to be exceptional in both cases. For example, in the most recent review in 2011, reviewers praised the high quality services and organization of the Core. MPlC's leadership who have substantial experience and have knowledge regarding all the techniques and equipment used in the core, and the facilities and equipment, which were considered state-of-the-art as the result of recent significant equipment upgrades and the acquisition of several pieces of new equipment including a Nikon Eclipse Ti-U microscope and a spinning disk confocal head. A detailed description of MPIC equipment and services is provided below.